Estimation of Global Scale Aerosol Properties

Information on the optical properties of aerosols at large or global scales is not readily available. Much less is known on the single scattering albedo and asymmetry parameter than on optical depth. More recently, systematic information on aerosols is forthcoming from observations, chemical transport models and satellites. An attempt has been made to merge aerosol information from several independent sources into a global characterization. Using truncated Empirical Orthogonal Functions (EOF) fitting, we derive monthly mean aerosol optical depth (AOD) at 0.55 μm using information from: the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model; the MODerate resolution Imaging Spectro-radiometer (MODIS); and the AErosol RObotic NETwork (AERONET). The single scattering albedo, the asymmetry parameter and the normalized extinction coefficient over the solar spectrum are estimated from GOCART data, MODIS Angstrom exponent and AERONET almucantar retrievals. The methodologies used to derive the merged product and selected results for a two year period will be presented.